Senior Software Engineer

Company Description ddx is a consultancy that takes projects from initial concept through to launch with integrated strategy, design, technology, and delivery teams. The company partners with Thai and multinational organizations, including One Bangkok, AMATA, BMW, Hitachi, and Marriott, on initiatives spanning urban development, digital products, and mobility. ddx focuses on asking critical questions early in the process to build the right solution, then executing quickly and efficiently. AI has been embedded in ddx’s ways of working since 2019, reflecting a strong commitment to innovation.

The company has teams based in London, Tokyo, Hong Kong, Bangkok, and Dubai, collaborating across regions on complex, forward-looking projects.

The Role A senior engineering role in the Technology team. You design, build and support complex software within a product or delivery stream. We work in an AI-native way, so AI-assisted development is part of your day-to-day work, from design and coding to testing and review.

You lead the technical work on complex features and components, and help the team solve difficult technical problems. You also mentor other engineers, advise on design and technical choices, and help the team improve how it builds, tests and releases software.

The role is based in the Bangkok office and reports to the Director of Technology. It sits at Level 5, “Ensure, Advise”, of the ddx Capability Framework, which follows SFIA 9 (the Skills Framework for the Information Age).

What You'll Do

• Design and build complex software components and services, from first build to live support.
• Use AI-assisted development, and hold AI-generated code and designs to the same standard as code written by people.
• Architect the solutions you lead, within the agreed wider architecture, and record the decisions and trade-offs.
• Compare design options, recommend one and explain the risks. Use prototypes or spikes to test a design before you commit to it.
• Review code and designs, and give clear feedback against the team’s coding, testing and security standards.
• Set the test approach for the work you lead, write automated tests, and work with QA to improve coverage.
• Lead integration work between services, APIs and third-party systems, including API contracts and versioning.
• Work with DevOps on the build and deployment pipelines, so that each change deploys through automated, repeatable steps and can be rolled back.
• Add monitoring and alerts for the features you deliver.
• Investigate complex defects and production incidents, find the root causes and fix them.
• Apply secure design and secure coding practice, and act on vulnerabilities in the components you own.
• Turn business and client requirements into technical designs and estimates.
• Integrate AI components into the software where they meet a defined need.
• Mentor software engineers and junior developers through pairing and code review.

What You'll Bring

• Several years of experience in software engineering teams that deliver production applications, including ownership of complex components.
• Hands-on experience of AI-assisted or AI-native development, with tools such as Claude in your daily work, and of checking what they produce.
• Strong skills in at least two of PHP, Node.js, TypeScript / ReactJS and SQL.
• Experience of building and deploying cloud-native applications, ideally on AWS.
• Experience of service and API design, and of integration with third-party systems.
• Experience of automated testing, CI/CD and production monitoring.
• Knowledge of secure coding (for example OWASP) and data protection (GDPR).
• Experience of mentoring engineers and reviewing their work.
• Clear communication with technical and non-technical people, including clients.
• Desirable: experience with ISO 27001 controls.

How You'll Work

• Under broad direction, planning your own technical work and deciding how to deliver the features you lead.
• Setting review checkpoints for AI use in your area, and guiding the team on when AI output can and cannot be relied on.
• Making technical decisions within the work you lead, and taking wider decisions to the Director of Technology.
• Making sure your own work, and the work you review, meets agreed standards for quality, security and maintainability.
• Proposing improvements to code, tools and practices, and helping put them in place.